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3 years ago

37,38 asap help show work

Chemistry

1 answer:

OLEGan [10]3 years ago

8 0

Answer: see below

Explanation:

When multiplying or dividing, use the smallest number of significant figures (sf) of the digits provided.

37(a) 24 × 3.26 = 78.24 2 sf × 3 sf --> round to 2 sf's

≈ 78

(b) 120 × 0.10 = 12 2 sf × 2 sf --> round to 2 sf's

= 12

= 2.5

(d) 53 × 1.53 = 81.09 2 sf × 3 sf --> round to 2 sf's

= 81

38(a) 4.84 ÷ 2.4 = 2.0167 3 sf × 2 sf --> round to 2 sf's

= 2.0

(b) 60.2 ÷ 20.1 = 2.995 3 sf × 3 sf --> round to 3 sf's

= 3.00

= 2.00

(d) 168 ÷ 58 = 2.896 3 sf × 2 sf --> round to 2 sf's

= 2.9

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Calculate [H3O+] and [OH−] for each of the following solutions at 25 ∘C given the pH. pH= 8.74, pH= 11.38, pH= 2.81

Gnom [1K]

Answer:

Explanation:

Given parameters;

pH = 8.74

pH = 11.38

pH = 2.81

Unknown:

concentration of hydrogen ion and hydroxyl ion for each solution = ?

Solution

The pH of any solution is a convenient scale for measuring the hydrogen ion concentration of any solution.

It is graduated from 1 to 14

pH = -log[H₃O⁺]

pOH = -log[OH⁻]

pH + pOH = 14

Now let us solve;

pH = 8.74

since pH = -log[H₃O⁺]

8.74 = -log[H₃O⁺]

[H₃O⁺] = 10⁻ $^{8.74}$

[H₃O⁺] = 1.82 x 10⁻⁹mol dm³

pH + pOH = 14

pOH = 14 - 8.74

pOH = 5.26

pOH = -log[OH⁻]

5.26 = -log[OH⁻]

[OH⁻] = 10 $^{-5.26}$

[OH⁻] = 5.5 x 10⁻⁶mol dm³

2. pH = 11.38

since pH = -log[H₃O⁺]

11.38 = -log[H₃O⁺]

[H₃O⁺] = 10⁻ $^{11.38}$

[H₃O⁺] = 4.17 x 10⁻¹² mol dm³

pH + pOH = 14

pOH = 14 - 11.38

pOH = 2.62

pOH = -log[OH⁻]

2.62 = -log[OH⁻]

[OH⁻] = 10 $^{-2.62}$

[OH⁻] =2.4 x 10⁻³mol dm³

3. pH = 2.81

since pH = -log[H₃O⁺]

2.81 = -log[H₃O⁺]

[H₃O⁺] = 10⁻ $^{2.81}$

[H₃O⁺] = 1.55 x 10⁻³ mol dm³

pH + pOH = 14

pOH = 14 - 2.81

pOH = 11.19

pOH = -log[OH⁻]

11.19 = -log[OH⁻]

[OH⁻] = 10 $^{-11.19}$

[OH⁻] =6.46 x 10⁻¹²mol dm³

5 0

3 years ago

Molar mass c3h8

maksim [4K]

Answer:

1. 44.11 g

2. 36.03 g

3. 8.08 g

4. 81.7%

5. 18.3%

Explanation:

1. 12.01+12.01+12.01+1.01+1.01+1.01+1.01+1.01+1.01+1.01+1.01=44.11

2. 12.01×3= 36.03

3. 1.01×8= 8.08

4.(36.03/44.11)×100= 81.7%

5. (8.08/44.11)×100= 18.3%

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2 years ago

When an object falls toward the ground due to gravity, what type of energy becomes kinetic energy?

Goshia [24]

OPTION C

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3 years ago

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As you go down a family or group on the periodic table *

pickupchik [31]

Answer:

The elements become less reactive.

Explanation:

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction and reactivity increases because of greater electron affinity.

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3 years ago

To arrive at the number of hydrogen atoms, What can be said about the relationship between the number of hydrogen atoms and the

Semenov [28]

Answer:

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3 years ago